Method and apparatus for remotely displaying a list by determining a quantity of data to send based on the list size and the display control size

ABSTRACT

A system and method for remotely displaying a plurality of data items is disclosed. The system determines a total quantity of displayable data items and optionally receives an indication of a display control size from a remote client. The server stores a threshold value indicating a relationship between a quantity of data items and a size of a display control. The server compares the quantity of data items and the received indication of the display control size. If the comparison exceeds the threshold value, the server sends a subset of the items to the remote client for display, and sends additional items as requested by the remote client. If the comparison is less than the threshold value, the server sends each of the items to the remote client for display. The server repeats this comparison for changes in the quantity of data items or the size of the display control.

PRIORITY CLAIM

This application is a continuation of and claims priority to U.S.application Ser. No. 12/207,436, filed on Sep. 9, 2008, the entirecontents of which is incorporated by reference herein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to the following co-pending commonly-ownedpatent applications: “METHOD AND APPARATUS FOR REMOTELY DISPLAYINGSCREEN FILES AND EFFICIENTLY HANDLING REMOTE OPERATOR INPUT,”application Ser. No. 12/207,448; “METHODS AND APPARATUS FOR DELIVERINGDOCUMENTS,” application Ser. No. 12/207,425; “METHOD, SYSTEM, ANDAPPARATUS FOR SCANNING AND IMPORTING DOCUMENTS,” application Ser. No.12/207,449; “METHOD AND APPARATUS FOR DISPLAYING A MENU FOR ACCESSINGHIERARCHICAL CONTENT DATA INCLUDING CACHING MULTIPLE MENU STATES,”application Ser. No. 12/207,442; and “METHOD, SYSTEM, AND APPARATUS FORSECURE DATA EDITING,” application Ser. No. 13/536,593; the entirecontents of each of which is incorporated by reference herein. Also,this application is related to the issued patent “METHOD, SYSTEM, ANDAPPARATUS FOR SECURE DATA EDITING,” issued as U.S. Pat. No. 8,234,219,the entire contents of which is incorporated by reference herein.

TECHNICAL FIELD

The present system relates in general to systems for displaying lists atremote locations, and more specially to an intelligent system fordisplaying list data on a remote display control by potentially sendingonly a subset of the list data to a remote client machine based on thequantity of list data to be displayed and the size of the displaycontrol at the remote client machine.

BACKGROUND

Software which displays lists of data enables an operator such as adatabase administrator or a database user to scroll through andselectively view vast amounts of data from a manageable interface suchas a display control. Specifically, such software enables the operatorto view a subset of the displayed data and to input one or morecommands, such as a scroll up command or a scroll down command, to thedisplay control, which cause the display control to display a differentsubset of the displayed data.

To indicate to the operator that such an input is appropriate, thedisplay control may include a scroll bar, scroll arrow, or othersuitable indicia. The operator may use an input device such as a mouse,a scroll-wheel, or a keyboard to input the command to scroll to adifferent subset of the data. Certain display controls may display suchscrolling by displaying a new subset of the data items havingsubstantially the same list items as the previously displayed (i.e.,pre-scrolled) subset of the data, but with at least one item removed andat least one item added to the subset. In this way, certain displaycontrols sequentially display a plurality of subsets of data to give theoperator the impression that he or she is scrolling through a large listof data items.

Certain display controls also enable the operator to modify the size ofthe display control used to display a list of data items. For example,certain software may enable an operator to select a resize indicator ofa list control and indicate a new size for the list control, thusenabling the operator to decide whether the list control should be sizedto display 50 list items or 5 list items. This determination may belimited based on one or more physical limitations of the hardwareexecuting the display control, such as monitor or display size and/orprocessor speed. So long as the operator is within the hardwareconstraints of the system, such display controls enable the operator tocustomize the control to simultaneously display a useful quantity ofdata. For example, the operator may determine that simultaneouslyviewing 50 data items is useful when a list includes thousands of dataitems, and may decide that simultaneously viewing only 5 data items isuseful for a list having fewer than one hundred data items.

When such display software is implemented in a network environment,where bandwidth can be at a premium, it is desirable to enable anoperator to control the amount of data sent over the networkedconnection. Thus, certain known software is configured to display aplurality of list data items in a remote display control by operating ineither a virtual mode or a non-virtual mode.

Software that is configured to display list data in virtual mode using aremote display control sends only the subset of data needed to fill thedisplay control at a given time. For example, such software may send 50data items out of thousands of data items to a remote display controlsized to display only 50 entries simultaneously. Such software,operating in virtual mode, sends additional data as it is needed, suchas based on the operator scrolling through the list, deleting data itemsfor the list, etc. For example, if the operator inputs an up-arrowkeystroke, virtual mode software may send data representing the dataitem immediately above the previously top-positioned data item. Itshould be appreciated that software configured to operate in virtualmode as described, though minimizing initial bandwidth usage (i.e., onlythe displayable items are initially sent), requires constant ornear-constant network connectivity (i.e., each changed in the displayedset of data requires a small amount of data to be sent).

Software configured to operate in non-virtual mode sends datarepresenting each of the data items upon initialization or creation ofthe display control. For example, regardless of the size of the displaycontrol, if a list includes 200 data items, remote display softwareoperating in non-virtual mode sends all 200 items to the displaycontrol. The display control stores the sent data, and internallydetermines which of the stored data items to display based on operatorinput. It should thus be appreciated that an operator can scroll throughthe data items without the display control receiving additional dataover the network connection. It should be appreciated that suchnon-virtual software reduces the need for constant or near-constantnetwork connectivity, but requires substantial initial data throughputto send the entire list of data items upon initialization of the displaycontrol.

The software described above requires a software developer to make adetermination during coding of whether to implement the software invirtual or non-virtual mode. Thus, such software lacks the flexibilityto enable a determination of network capabilities on a remote user byremote user basis. Moreover, such software lacks the ability todetermine whether to operate in virtual mode or in non-virtual modebased on the hardware capabilities of the computer system running thedisplay control. The need for the developer to determine whether thesoftware is to operate in virtual mode or non-virtual mode atdevelopment time is particularly problematic in the insurance industry,wherein insurance professionals use hardware having vastly differingcapabilities to simultaneously access a single remote server.

SUMMARY

The system disclosed herein overcomes the described deficiencies of theprior art by providing an intelligent system for remotely displaying asubset of a plurality of data items in a navigable list. The disclosedsystem displays such a list by determining a characteristic of a displaycontrol on a remote client machine, the characteristic being specific tothat remote client machine. For example, the system may determine adisplay control dimension. The system also stores a threshold value foruse in determining whether to display a subset of data items in eithervirtual mode (i.e., only the displayed items are sent for a givensubset) or non-virtual mode (i.e., each data item is sent prior todisplaying the subset). By comparing the total quantity of data items inthe list of data items to the characteristic specific to the remoteclient machine, the system determines whether or not the threshold valueis exceeded. If the threshold value is met or exceeded, the system maydisplay the data items in virtual mode. If the threshold value is notexceeded, the system may display the data items in non-virtual mode. Forany changes made to the size of the data display control on the clientmachine, the disclosed system recalculates the relationship discussedabove and re-compares the relationship to the threshold value. Suchre-comparison may result in a change from operating in virtual mode tonon-virtual or vice versa. Moreover, a change in the data for displaycan result in a change from operating in non-virtual mode to operatingin virtual mode. Thus, the disclosed system enables a real-time, dynamicdetermination of whether to operate in virtual mode or non-virtual modebased on the size of the display controls of a plurality of remoteclients and the quantity of items for display.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram of an example system architecture forimplementing the intelligent list display system disclosed herein.

FIG. 2 is a flow chart of an example process for intelligentlydetermining how much list data to send to a remote client based on thequantity of list data and also based on the size of the display controlof the remote client.

FIGS. 3 to 8 are combination screen shots of a display control of aremote client and message flow diagrams corresponding to the screenshots for determining how much of the list data to send to the remoteclient.

DETAILED DESCRIPTION

FIG. 1 is a block diagram of an example system architecture forimplementing the intelligent list display system disclosed herein.Specifically, FIG. 1 illustrates a schematic block diagram of a hostdevice (e.g., host device 100) for implementing the disclosedintelligent list display system. In the example architecture, the hostdevice 100 includes a main unit 102 which preferably includes one ormore processors 104 electrically coupled by an address/data bus 106 toone or more memory devices 108 other computer circuitry 110, and one ormore interface circuits 112. The processor 104 may be any suitableprocessor. The memory 108 preferably includes a combination of volatilememory and non-volatile memory. Preferably, the memory 108 stores asoftware program that interacts with the other devices in the system asdescribed below. This program may be executed by the processor 104 inany suitable manner. The memory 108 may also store digital dataindicative of documents, files, programs, web pages, etc. retrieved froma remote client 152, such as modifications made remotely to a displaycontrol of a remote client 152, modifications made remotely to aplurality of list items displayed on the remote client 152, or inputsrepresenting scrolling or other navigation of the plurality of listitems using the remote client 152. In one example described in moredetail below, a display control of the remote client 152 may display orshow a subset of a plurality of list items in either virtual mode ornon-virtual mode.

The interface circuit 112 may be implemented using any suitableinterface standard, such as an Ethernet interface and/or a UniversalSerial Bus (USB) interface. One or more input devices 114 may beconnected to the interface circuit 112 for entering data and commandsinto the main unit 102. For example, the input device 114 may be akeyboard, mouse, touch screen, track pad, track ball, isopoint, and/or avoice recognition system.

One or more displays 120 or printers, speakers, and/or other outputdevices 116 may also be connected to the main unit 102 via the interfacecircuit 112. The display 120 may be a cathode ray tube (CRT), liquidcrystal display (LCD), or any other type of display. The display 120 maygenerate visual displays of data generated during operation of the hostdevice 100, such as those screen shots described below. For example, thedisplay 120 may be used to display a display control including aplurality of list items, the display control operating in either virtualor non-virtual mode depending on a dimension of the display control. Itshould be appreciated that the display 120 may not be present in thedisclosed intelligent system for displaying list data. Specifically, ifthe disclosed system is configured to display list data on remoteclients such as remote client 152, a display 120 may not be needed.

One or more storage devices 118 may also be connected to the main unit102 via the interface circuit 112. For example, a hard drive, a compactdisc (CD) drive, a digital versatile disc (DVD) drive, a tape drive,and/or any other suitable storage device may be connected to the mainunit 102. The storage devices 118 may store any type of data used by thehost device 100 or sent to the remote client 152. In one example,described in more detail below, the storage device 118 storesinformation about a plurality of list data items for remotely displayingon the remote client 152. The information about the plurality of listdata items may include the list data items themselves, and may alsoinclude content data associated with the display items. The storagedevice 118 may store a threshold value such as a static decimal valuefor determining whether to display the plurality of display items invirtual mode or in non-virtual mode, as discussed below.

The host device 100 may exchange data with the one or more remoteclients 152 using a connection to network 140. The network connectionmay be any suitable network connection, such as an Ethernet connection,digital subscriber line (DSL), telephone line, coaxial cable, etc.Access to a host device 100 may be controlled by appropriate securitysoftware or security measures. An individual operator's access can bedefined by the host device 100 and limited to certain data and/oractions. Accordingly, operators of the system may be required toregister with one or more host devices 100. The data exchanged betweenthe host device 100 and the remote client 152 may include screen files(i.e., image data for display at the remote client 152), trapped eventsat the remote client 152 (i.e., scroll events, resize events, add dataevents, delete data events, etc.), and raw data including data aplurality of data items and any content data associated with the dataitems.

It should be appreciated that other suitable architectures arecontemplated by the disclosure herein. For example, architecturesincluding a plurality of remote clients 152, or architectures whereinthe host device 100 includes only a storage device 118 are contemplated.It should be appreciated that in these various contemplatedarchitectures, some or most of any processing performed to determinewhether to display list data items in virtual or non-virtual mode isperformed by one or more of the remote clients 152.

FIG. 2 is a flow chart of an example process for intelligentlydetermining whether to send list data to a remote client 152 in eithervirtual mode (i.e., sending a subset of the list data items) ornon-virtual mode (i.e., sending all of the list data items) based on aquantity of list data items and also based on a dimension of a displaycontrol executed by the remote client 152. Although the example process200 for intelligently determining whether to operate in virtual mode orto operate in non-virtual mode is described with reference to the flowchart illustrated in FIG. 2, it should be appreciated that many othermethods of intelligently determining whether to operate in virtual ornon-virtual mode are contemplated. For example, the order of certain ofthe blocks may be changed, and certain of the blocks described areoptional.

The process 200 of FIG. 2 may be executed by an intelligent list displaysystem such as a display system operating on host device 100. The hostdevice 100 may be acting as a server of list data items. The host device100 may serve these list data items to a remote client 152 for displayusing one or more display controls running thereon. It should beappreciated that the following description relates to the host device100 serving such list data item information to the remote client 152,and the remote client 152 enabling an operator to input various desiredoperations to perform with respect to the plurality of list data items.It should be appreciated that many other hardware configurations arecontemplated for executing process 200, such as hardware configurationswherein one or more of the decisions and/or actions indicated by process200 are performed by the remote client 152.

The process 200 of FIG. 2 begins with the host device 100 storing a listof data items in the memory device 118 of the host device 100 (block202). The list of data items may be stored based on user input at theinput devices 114, user input at the remote client 152, or from anothersuitable memory device such as a CD-ROM. The list of data items mayrepresent the displayable data for viewing by the operator at the remoteclient 152. The host device 100 also stores a threshold value (block202). The threshold value may be hard-coded into software running on thehost device 100, or may alternatively be entered by an operator usingthe one or more input devices 114 of the host device 100. Alternatively,the threshold value may be entered by an operator at remote client 152using a suitable input device to indicate a desired threshold value. Thethreshold value may be a ratio comparing the size of a display controlat a remote client 152 with the quantity of items in the list, and maybe used, as described below, to determine whether to remotely displaythe list items in virtual mode or in non-virtual mode.

It should be appreciated that the storage of the list of data items andthe threshold value may be performed without regard for the technicalspecifications of any remote client 152. That is, the storage of suchdata may be viewed as storing static data, without customization for aparticular remote client 152, for determining whether to remotelydisplay data in virtual mode or non-virtual mode.

The host device 100 may next receive an indication a dimension of adisplay control running on a remote client 152 (block 204). Thedimension may include a quantity of pixels (i.e., 400 pixels), a listitem display capacity (i.e., a maximum of 10 list items), or any othersuitable dimension. It should be appreciated that the display controldimension reflects a quantity of list items which are simultaneouslydisplayable using the display control of the remote client 152. Itshould be further appreciated that the dimension may vary from oneremote client to another based on each display control running on eachremote client 152. Specifically, if a first remote client 152 has alarger monitor or display device than a second remote client 152, thedimension of the display control for the first remote client mayindicate a capability to simultaneously display more list items than thesecond remote client.

The list display system next calculates a ratio between the receiveddisplay control dimension and the total quantity of items in the list ofdata items for display (block 206). The calculated ratio may represent apercentage of the total list data items which can be simultaneouslydisplayed using the display control of the remote client 152. Forexample, the list display system may receive an indication from a firstremote client 152 that the first remote client 152 is capable ofsimultaneously displaying 10 list data items using its display control.If the list of data items includes 100 total data items, the disclosedsystem may calculate a ratio of 10/100 or 0.1. This means that thedisplay control of the remote client 152 is capable of displaying 10% ofthe total list of data items at any given time. For a second remoteclient 152 which is capable of simultaneously displaying 25 data items,it should be appreciated that the ratio for the second remote client 152indicates that it can simultaneously display 25% of the total dataitems. It should thus be appreciated that by calculating a ratio (block206), the disclosed system customizes the determination of whether tooperate in virtual or non-virtual mode on a remote client by remoteclient basis. That is, for the same quantity of list data items, a firstremote client may have a first associated ratio and a second remoteclient may have a different, second ratio based on the hardware profileand/or operator preferences of each client.

The host device 100 compares the calculated ratio for a particularremote client 152 with the stored threshold value, which is applicablefor all remote clients 152 (block 208). The result of this comparisonmay indicate whether the host device 100 should serve the list dataitems to the remote client 152 in virtual or non-virtual mode.Specifically, if the ratio exceeds the threshold value (block 208), thehost device 100 stores data indicating that the list data items are tobe served to the remote client 152 for display in non-virtual mode(block 210). It should be appreciated that if the ratio represents apercentage of the total list items which can be simultaneously displayedfor a given remote client 152, the disclosed system displays the listitems in non-virtual mode when a relatively high percentage of the listitems can be simultaneously displayed (i.e., the display control isrelatively large). On the other hand, if the ratio does not exceed thethreshold value (block 208), the list display system stores dataindicating that the list is to be displayed in virtual mode (block 216).It should be appreciated that the system displays the list items invirtual mode when a relatively small percentage of the list items can besimultaneously displayed (i.e., the display control is relativelysmall).

If the list display system stores an indication that the list is to bedisplayed in non-virtual mode for a given remote client 152 (block 210),the host device 100 sends the entire list of data items to the remoteclient 152 for display by the display control (block 212). If thedisplay control of the remote client 152 is not sized to enable each ofthe data items to be simultaneously displayed, the display control ofthe remote client 152 determines how to display a subset of the dataitems. For example, the remote client 152 may determine that the displaycontrol should include a scroll bar and a plurality of arrow buttons toenable an operator to scroll upward and/or downward through the dataitems. Further, the remote client 152 may ensure that the appropriatedisplay items are displayed as the operator scrolls through the list,and may enable the operator to manipulate the contents of the list suchas by adding or deleting list data items. It should be appreciated thatin non-virtual mode, as described, the host device may not need to sendand/or receive data items over the network 140 after sending the initialset of data items. Rather, the remote client 152 locally stores each ofthe data items and locally handles any manipulation and display of thoseitems.

The disclosed list display system intelligently determines how todisplay a plurality of list items by continually analyzing whether tooperate in virtual mode or in non-virtual mode. Specifically, even ifthe system is operating in non-virtual mode, the host device 100 isconfigured to receive an input from an operator representative of achange in the display control dimension (block 214). For example, thedisclosed remote client 152 may include a handler for trapping andsending a display control window resize event indicating a new displaycontrol window size to the host device 100. Such an indication includesa display control dimension received from the client (block 204). Forany received display control window resize events, the host device 100re-calculates the ratio between the current display control dimensionand the quantity of items in the list of data items (block 206). Basedon this newly calculated ratio (i.e., the ratio reflecting the new sizeof the display control), the disclosed system determines whether tocontinue displaying the plurality of list items in non-virtual mode orto begin displaying the plurality of list items in virtual mode. Thisdetermination is made, as discussed above, based on whether there-calculated ratio exceeds the threshold value (block 208).

If the disclosed list display system determines that the ratio betweenthe received display control dimension and the quantity of items in thelist of data items does not exceed the threshold value (block 208), thesystem stores data indicating that the list is to be displayed at theremote client 152 in virtual mode (block 216). To display the list invirtual mode, the host device 100 sends a subset of the list of dataitems to the remote client 152, with the quantity of items in the subsetbeing determined based on the display control dimension (block 218).That is, the system sends a subset of items containing only a quantityof items which can be simultaneously displayed in the display control ofthe remote client 252.

Upon sending the appropriate subset of list data, the host device 100waits for an appropriate operator input to be trapped by the remoteclient 152 and sent to the host device 100 (block 220).

It should be appreciated that for simplicity, only two types of operatorinput are possible in the illustrated embodiment. First, the illustratedembodiment of the process 200 is capable of handling operator inputrepresenting a desire to scroll through the data to view at least onelist data item not currently displayed by the display control. Second,the illustrated embodiment of the process 200 is capable of handlingoperator input representing a resizing of the display control of theremote client 152. It should be appreciated that various other types ofinput are possible in other, un-illustrated embodiments, such as inputsindicating a desire to add, delete, or otherwise modify the list data,inputs indicating a desire to view content data associated with the listdata, or inputs indicating a desire to reorganize the displayed listdata within the display control.

If the input received from the operator represents a desired scroll ofthe data items displayed in the display control (block 222), thedisclosed system determines, based on the input, which new data itemswill be displayed after scrolling and sends any appropriate new dataitems to be displayed to the remote client 152 (block 224). The remoteclient 152 may delete or otherwise fail to store any of the data itemswhich are no longer visible after scrolling. Thus, the remote client 152may retain in its memory only the list data items being currentlystored.

After sending the needed data to enable the remote client 152 toappropriately display the appropriate new subset of data items (block224), the disclosed system again waits for operator input (i.e., eithera scroll input or a resize input) (block 220).

If, while the host device 100 is awaiting operator input, the operatormakes an input that does not indicate a desired scroll (i.e., in thetwo-input illustration of FIG. 2, the input indicates a change in sizeor dimension of the display control) (block 222), the disclosed systemreceives an indication of the display control dimension after the changein size (block 204). Using this newly-received dimension of the displaycontrol, the host device 100 recalculates the ratio between the displaycontrol dimension and the quantity of items in the list of data items(block 206). The host device 100 then determines whether thenewly-calculated ratio exceeds the threshold value (block 208). If so,the host device 100 updates the data indicating the mode for sendinglist items to indicate non-virtual mode (block 210). If thenewly-calculated ratio does not exceed the threshold value (block 208),the disclosed system updates the stored data to reflect sending invirtual mode.

As discussed above, the disclosed system may calculate the size of listdata to be displayed by determining a quantity of list items to bedisplayed. Alternatively, the disclosed system may calculate the size ofthe list data, for purposes of calculating a relationship such as aratio between the list data and the display control, by analyzing a sizeof the data items in bytes. Thus, one hundred list items may cause thesystem to operate in virtual mode if the total size of the list itemsexceeds fifty kilobytes, but one hundred list items may cause the systemto operate in non-virtual mode if the total size of the list items doesnot exceed fifty kilobytes. Similarly, the calculation of the size ofthe list items may be based on a number of characters in the list items,a size of content data associated with the list items, or any othersuitable indicator of a size of the list data.

It should be appreciated that based on the resized display control, thedisclosed system may determine that a change from displaying the listitems in virtual mode to non-virtual mode is appropriate (i.e., if thesize of the display control is increased such that the ratio isincreased to above the threshold value). Thus, the disclosed intelligentdata item display system is configured to continually switch betweenvirtual and non-virtual modes in real-time based on appropriate operatorinputs. The disclosed system is also configured to send necessary data,when operating in virtual mode, to enable an operator to scroll throughthe plurality of list data items despite only a subset of the itemsbeing stored on the remote client 152 at any given time.

The disclosed system may be configured to change from operating innon-virtual mode to operating in virtual mode only if the data to bedisplayed changes. That is, a change in the data to be displayed, ifcoupled with an appropriate change in size of the display control, mayrepresent the only set of conditions for which the system switches fromoperating in non-virtual mode to operating in virtual mode. Further, thedisclosed system may be configured to change from operating innon-virtual mode to operating in virtual mode only if the data to bedisplayed is modified to include additional data. That is, even areduction in the data to be displayed, coupled with an appropriatechange in size of the display control, lowers the ratio between the sizeof the display control to a quantity below the threshold, the disclosedsystem may not switch from operating in non-virtual mode to operating invirtual mode. Rather, the only time such a switch may be made is ifadditional data to be displayed is added.

It should be appreciated that by displaying a list at a remote client152 in non-virtual mode, the disclosed system minimizes ongoing orcontinuous use of network resources because data only needs to be sent asingle time. It should also be appreciated, however, that the singletime sending of data may represent a significant use of bandwidth, asthe disclosed system initially sends the entire set of list data. Itshould also be appreciated that a continuing network connection may benecessary, as the disclosed system may continuously detect changes inthe dimensions of the display control of the remote client 152 andupdate the determination whether to act in virtual or non-virtual modebased on the changes in dimension.

It should be further appreciated that by displaying a list at a remoteclient 152 in virtual mode, the disclosed system minimizes the initialuse of bandwidth but increases the ongoing or continuous need forbandwidth, as browsing or scrolling through the list of data itemsrequires additional data items to be sent to the remote client 152.

The disclosed system for displaying a list of data items may also enablean operator at a remote client 152 to modify the quantity of data itemsstored in the storage device 118. For example, the disclosed system mayenable the operator to add and/or delete data items from the list ofdata items. If a system according to the instant disclosure enables thisfunctionality, the host device 100 may receive a message indicating theoperator's desire to add or delete a data item and may make theappropriate addition or deletion in the storage device 118. Moreover,since the total quantity of data items in the list of items may bealtered based on such additions and/or deletions, the disclosed systemmay recalculate the ratio between the received display control dimensionand the quantity of items in the list of data items even if the displaycontrol dimension has not changed.

Depending on the functionality of the system, the host device 100 mayupdate the ratio which is compared to the threshold value based on theoccurrence of any event which modifies at least one of the quantitiesused to calculate the ratio. Thus, modification of any of the quantitiesof the ratio may result in a change from displaying the list items invirtual mode to displaying the list of items in non-virtual mode or viceversa.

One or more of the data items in the list of data items may beassociated with content data. The system may thus enable an operator toselect one or more of the list items using an input device connected tothe remote client 152, and may send the content data associated with thelist device for viewing on the remote client 152. The system may sendthis data only in response to an operator selecting such a list item,regardless of whether the system is operating in virtual mode or innon-virtual mode. Alternatively, the system may send the content dataassociated with any list items which are sent according to the process200. For example, if the system is operating in non-virtual mode, thesystem may initially send all the list items and all the associatedcontent data. If the system is operating in virtual mode, the system maysend only the content data associated with the send list items, suchthat as an operator browses through the list items, the content datastored locally on the remote client 152 is updated appropriately.

Alternatively, the disclosed system may send only the content dataassociated with the displayed list items regardless of whether thesystem is sending list items in virtual mode or non-virtual mode. Thus,the system may determine that it is operating in non-virtual mode andmay send each of the list data items to the remote client 152.Regardless of its operation in non-virtual mode, the system may sendonly the content data associated with the list data items currentlydisplayed by the display control. Thus, the disclosed system may beviewed as determining which list items to display in either virtual ornon-virtual mode, and may be further viewed as sending the content dataassociated with the displayed list items in only non-virtual mode.

The threshold value stored by the disclosed system may be selected onlyonce, such as being hard-coded in the software running on the hostdevice 100. The threshold value may represent a programmer's perceptionof an appropriate percentage of the total number of list items that canbe simultaneously displayed wherein utilizing the extra bandwidthinitially required to operate in non-virtual mode is justified.Alternatively, the threshold value may be customized to one or more of aplurality of remote clients 152 in communication with the host device100. For example, a threshold value may be dependent upon a hardwareconfiguration of a remote client 152, such as a quantity of memory, aprocessor speed, or a size of a display device such as a monitor. Theoperator at the remote client 152 may select an appropriate thresholdvalue based on the network connection and/or hardware capabilities ofthe remote client 152 used to access the remote list data displaysystem.

The threshold value may reflect additional factors than simply arelationship between a quantity of list items and a dimension of adisplay control. For example, the threshold value may reflect thehardware and/or network capabilities of a remote client 152 such that ahard-coded threshold value is usable to customize thevirtual/non-virtual determination made based on the hardwarecapabilities of an individual remote client. For example, a thresholdvalue may be selected by multiplying, dividing, adding, or subtracting aquantity of list items, a dimension of a display control, a networkconnection speed, or a hardware capability indicator of the remoteclient 152. It should be appreciated that if the threshold valuereflects such additional factors, the calculation of the ratio forcomparison to the threshold value should also reflect the additionalfactors.

For example, a threshold value of 0.75 may be selected by a programmeror system operator. This value may be arrived at by multiplying a ratioof 1/2 (representing the ratio of the dimension of the display controlto the quantity of list items) by a factor of 1.5. When determining theratio for a remote client 152, the disclosed system may divide the sizeof the display control by the quantity of list items and multiply theresult by 1.0 if the connection is a dial-up or other relatively slowconnection and by 2.0 if the connection is a broadband or otherrelatively fast connection. Thus, even if a ratio of the size of thedisplay control to the quantity of list items is relatively smaller than1/2 (i.e., a ratio of 2/5), the disclosed system may still elect tooperate in non-virtual mode (i.e., it may initially send datarepresenting each of the list items) if the remote client 152 isconnected to the host device 100 via a broadband connection (i.e., aratio of 2/5 multiplied by a connection factor of 2.0 results in afactor of 0.8, which exceeds the threshold value of 0.75 and thereforeindicates that the disclosed system should operate in non-virtual mode).It should be appreciated that any other appropriate factors may be builtinto the calculation of the threshold value and ratios, such as operatorpreference, hardware capability, network access cost, network accessspeed, usage pattern, and/or any other suitable factor.

FIG. 2 refers to calculation of a ratio between the received displaycontrol dimension and the quantity of items to be displayed. It shouldbe appreciated that the system disclosed herein is not limited to thecalculation of such a relationship as a ratio. Rather, the disclosedsystem may use any quantifiable representation of a relationship betweenthe capacity of the display control and the quantity of data to displayto determine whether to operate in virtual mode or in non-virtual mode.For example, the disclosed system may use a product of two numerals, ormay use a more complex mathematical formula to quantify the notedrelationship.

It should be further contemplated that the disclosed system is notlimited to quantifying a relationship solely between the size of thedisplay control and the amount of data to be displayed in order todetermine whether to operate in virtual mode or in non-virtual mode. Asnoted above, the disclosed system may use additional factors, such asnetwork speed, hardware capability, or operator preference to generate aquantity indicative of whether the system should operate in virtual modeor in non-virtual mode. Moreover, this determination need not be basedat all on either size of the display control or the quantity of data tobe displayed. For example, the determination in may be based solely onnetwork speed, may be based solely on the absolute size of the displaycontrol, or may be based on some other appropriate factor. It should beappreciated that the disclosed intelligent system automaticallydetermines whether to operate in virtual or non-virtual mode based onsome potentially changing, quantifiable characteristic of either theremote client 152, the host machine 100, or the network 140.

The disclosed system may determine whether to operate in virtual mode orin non-virtual mode based on a size of a display control which isfixed—that is, the host device 100 may determine whether to send all ofthe data items or a subset of the data items by calculating a ratiobased on a fixed-size display control. For example, if the disclosedsystem provides a display control at the remote client 152 which is afixed size, such as 10 list data items, the disclosed system maycalculate a ratio based on the relationship between the fixed size andthe potentially variable quantity of data items to display. It should beappreciated that the remote client 152 may not need to repeatedly senddata indicating the size of the display control, and may send such dataonly once or not at all. Thus, the disclosed system provides a dynamicsystem for displaying menu items where the decision to operate invirtual or non-virtual mode is made in real time based on a ratiobetween a potentially changing total quantity of items to display and afixed display control size.

The disclosed system may be configured to receive data from the remoteclient 152 indicating the occurrence of various events at the remoteclient 152. For example, the disclosed system may be configured toreceive not only data indicative of an operator scroll or displaycontrol resize input, but may also receive data indicative of additionsof list items, deletions of list items, updates of list items,reordering of list items, filtering of list items, duplication of listitems, updates of content data associated with list items, page-ups,page-downs, scrolls to the beginning or end of the list, jumps toparticular list items (i.e., based on an alphabetical list of items),sort requests, and any other suitable input which could be handled by asuitable handler. In various embodiments, the disclosed system analyzesone or more of these inputs and modifies the calculated ratio orrelationship based on these inputs to determine whether to continueoperating in virtual or non-virtual mode or to change the operatingmode.

The remote client 152 may store data previously sent by the host device100 regardless of the mode in which the host device 100 is operating.For example, if the host device 100 is operating in virtual mode, thehost device 152 may store data indicating a first 5 list items of 100total list items. The host device 100 may determine (or store dataindicating) which list items have been previously stored or cached onthe remote client 152. Based on the determined list items, the hostdevice 100 may not re-send certain items. In the example above, if anoperator provides a scroll to bottom input, the host device 100 may senddata representing the last 5 list items of the 100 total list items. Ifthe operator subsequently enters a scroll to top input, the disclosedsystem may determine that the first 5 items have been previously storedor cached on the remote client 152, and may therefore not resend thefirst 5 items. Rather, the host device 100 may rely on the remote client152 to display the cached first 5 items of 100 total items. The hostdevice 100 may compare the displayed items to the items stored in thestorage device 118 to determine whether the list items have beenmodified. The host device 100 may send the current list items stored inthe storage device 118 only if the corresponding cached list items havebeen modified.

The disclosed system may be implemented substantially using softwareinstalled on the remote client 152. For example, the remote client 152may store a threshold value and may store data about the list of itemsof the storage device 118, such as the quantity of list items. Theremote client 152 may determine the size of the display control and mayappropriately calculate the ratio between the display control dimensionand the quantity of items in the list of data items. Based on thecomparison of this ratio with the threshold value, the remote client 152may determine whether to operate in virtual mode or non-virtual mode.According to the determination made by the remote client 152, the remoteclient 152 may request the required data from the host device 100. Forexample, if the remote client 152 determines that it is operating invirtual mode, the remote client 152 may request only the data requiredto fill the display control as determined by the remote client 152. Ifthe remote client 152 determines that it is operating in non-virtualmode, the remote client 152 may request data representing all of thelist items from the host device 100. The remote client 152 may beconfigured to enable an operator to modify the quantity of list itemsstored in the remote storage device 118. The host device 100 may senddata indicating a current quantity of list items stored in the storagedevice 118 each time any operator at any host device 152 modifies thequantity of list items. It should be appreciated that the host device100 may thus be responsible for ensuring that the remote clients 152 areaware of the current content of the storage device 118.

It should be appreciated that by offloading certain processing tasksfrom the host device 100, the disclosed system may rely more heavily onthe processing capabilities of the remote client 152 and may requireless processing capability from the host device 100. Moreover, it shouldbe appreciated that offloading such processing tasks may result insimpler handling of operator input events, as data indicating each eventmay not need to be sent via the network 140 for handling by the hostdevice 100, as in the process 200 described above with reference to FIG.2.

In contrast to networked implementations such as the implementationsdescribed above, the disclosed system may also be implemented on asingle computer or set of processing hardware. For example, in a systemwherein processing resources are relatively scarce (i.e., a system witha relatively small amount of Random Access Memory (RAM)), the process200 may be followed to determine whether to load an entire set of listitems or a subset of the list items into relatively faster andrelatively more scarce RAM from a more permanent (and slower) storagedevice such as a hard disk, a tape drive, or an optical drive. In such asystem, the relatively small amount of RAM may necessitate care indetermining what data to load on the RAM. It should be appreciated thatloading data into RAM may enable faster access by the processor, suchthat one goal of a memory management sub-system of a computing system isto store the most frequently accessed data in the system's RAM. That is,the memory management sub-system may attempt to maximize the computingresources of system by providing relatively fast access to frequentlyused data and by providing relatively slower access to less-frequentlyused data.

Operation of a system in virtual mode may be achieved by loading only asubset of data from a relatively slow storage medium (i.e., a hard disk)into the relatively scarce, relatively faster storage medium (i.e., RAM)prior to display. This enables display while requiring a minimum amountof the relatively scarce, relatively faster storage medium. However, itshould be appreciated that for the system to display data not includedin the subset of the data, an additional transfer of the new data isnecessary. Alternatively, operation of a system in non-virtual mode maybe achieved by loading the full set of data to be displayed into therelatively faster storage medium. This may enable display of the fullset of data without requiring additional data transfer from the harddisk to the RAM. Though operation in non-virtual mode provides fasteraccess to the data, it should be appreciated that such non-virtualoperation may consume a relatively higher amount of the relativelyscarce faster memory resources (i.e., RAM).

As discussed above with respect to process 200, the system may make thedetermination whether to operate in virtual mode or non-virtual mode(i.e., whether to store all of the data or only a subset of the data onin RAM) based on a ratio between a size of a display control provided bythe processor and a total size of the data items on the slower storagemedium. It should be appreciated that a higher ratio indicates that moreof the data items will be simultaneously displayed by the displaycontrol, and thus may indicate that it is more advantageous for thesystem to operate in non-virtual mode by making a single transfer of allthe list data items to the RAM.

FIGS. 3 to 9 each illustrate a screen shot of a display control of aremote client 152 and a message flow diagram corresponding to the screenshot which illustrates the determination of whether to operate invirtual or non-virtual mode. FIGS. 3 to 9 each include a screen shotsection 300 and a message flow diagram section 350. In the embodimentsillustrated by FIGS. 3 to 9, the remote client 152 is a thin client—thatis, most of the processing, including the determination whether tooperate in virtual or non-virtual mode, is made by the host device 100and the appropriate data for display is sent from the host device 100 tothe remote client 152 for display. It should be appreciated that forFIGS. 3 to 9, the server 360 illustrated in the message flow diagramsection 350 corresponds to the host device 100, and the client 370corresponds to the remote client 152. Alternatively the server 360 andthe client 370 may represent software modules disposed across aplurality of physical devices.

Screen shot sections 300 of FIGS. 3 to 9 include a display control 310as displayed by the remote client 152. The display control 310 isentitled Display_Control and is labeled accordingly. It should beappreciated that in various embodiments, the display control 310 may bedisplayed on the display device 120 of host device 100, enabling anoperator at the host device 100 to view a plurality of data list itemsstored on the storage device 118 of the host device 100.

The display control 310 of FIGS. 3 to 9 includes various indicatorswhich enable an operator to input desired scrolling of the displayeddata. For example, the display control 310 includes a slider 312 whichenables an operator to scroll upward and/or downward through the list ofdata list items. The slider 312 is positioned in a slider bar 313 whichindicates a relative position of the slider with respect to the list ofdata items and which indicates an amount by which the list can bescrolled. The display control 310 also includes arrow buttons 314 a and314 b which enable the operator to scroll through the list items. Forexample, by selecting arrow buttons 314 a or 314 b, the operator cancause the slider 312 to slowly move within the slider bar 313, and cansimultaneously cause the displayed data list items to scroll in anappropriate direction. It should be appreciated that the arrow buttons314 a and 314 b may enable such scrolling in a more controlled fashionthan slider 312. It should be appreciated that the slider 312 and thearrow buttons 314 a and 314 b may not be displayed in scrolling isimpossible—that is, such scrolling indicators may not be displayed ifthe display control is appropriately sized to display each of the datalist items stored in the storage device 118.

Display control 310 includes a resizer 316 which, when selected using anappropriate input device, enables an operator to resize the displaycontrol 310.

It should be appreciated that in the process 200 described above, thehost device 100 is configured to receive input provided by the operatorusing either the scroll indicators or the resizer.

FIGS. 3 to 9 each also illustrate a message flow diagram section 350which includes a message flow diagram 380 indicating any messages whichflow between the server 360 (i.e., the host device 100) and the client370 (i.e., the remote client 152), illustrated as arrows indicating anoriginator and a destination. The message flow diagram sections 350 ofFIGS. 3 to 9 also illustrate a plurality of processing decisions made byeach device, illustrated as device-specific boxes. As used herein,processing decisions refer to determination and/or storage of values ofvariables, comparisons of variables to each other, determination ofdisplay modes (i.e., virtual or non-virtual), and display operations. Itshould be appreciated that unlike in the process 200 illustrated above,the disclosed client 370 is configured to trap and the disclosed server360 is configured to handle scroll events, resize events, and add/deletedata item events. Thus, for any such event, FIGS. 3 to 9 illustrate anappropriate message representing the event and the handling thereof.

Referring specifically to FIG. 3, the display control 310 includes aplurality of data list items Data_List_Item_1 318 a, Data_List_Item_2318 b, Data_List_Item_3 318 c, Data_List_Item_4 318 d, Data_List_Item_5318 e, Data_List_Item_6 318 f, Data_List_Item_7 318 g, Data_List_Item_8318 h, Data_List_Item_9 318 i, and Data_List_Item_10 318 j. It should beappreciated that Data_List_Item_10 318 j is illustrated as onlypartially displayed within the display control 310, but that forpurposes of determining the size of the display control 310, ten (10)different data list items are displayed. The slider 312 is displayed aspositioned at the top of the slider bar 313, indicating that the displaycontrol 310 is displaying at least the first data list item 318 a.

It should further be appreciated that a plurality of additional datalist items are not displayed in the display control 310, includingData_List_Item_11 318 k, Data_List_Item_12 318 l, Data_List_Item_13 318m, Data_List_Item_14 318 n, and Data_List_Item_15 318 o. Theseadditional data list items may be stored on the storage device 118 ofhost device 100.

Referring now to the message flow diagram section 350 of FIG. 3, themessage flow diagram 380 illustrates a message flow including twomessages 381 and 382. The message flow diagram 380 further illustratesprocessing decisions 361, 362, 363, 364, 365, and 372. The message flowillustrated begins when the client 370 sends a request for data listitem data 381 to the server 360. The request includes data indicatingthat a dimension of the currently displayed display control 310 is 10.The size of 10 indicates that 10 data list items are simultaneouslydisplayable in the display control 310.

Upon receiving such a message, the server 360 determines that the totalquantity of displayed items stored in the storage device 118 is 15displayed items, as indicated by processing decision 361. It should beappreciated that since the display control 310 is illustrated as thefirst display control, the server 360 may have made such a determinationas to the quantity of display items by analyzing the storage device 118.Alternatively, an appropriate variable may have already been storedwithin the memory of the server 360. The server next determines that theapplicable threshold value for the display control is 0.4, as indicatedby processing decision 362. As discussed above, this threshold value maybe entered by an operator, hard-coded by a programmer, or determined inany other suitable way.

To determine whether to operate in virtual mode or in non-virtual mode,the disclosed system determines the ratio between the display controldimension and the total number of display items. Specifically, thedisclosed system determines the ratio to be 0.67, as indicated byprocessing decision 363. The system next compares the ratio of 0.67 tothe threshold value of 0.4 and determines that the ratio exceeds thethreshold value, as indicated by processing decision 364. Based on thiscomparison, the disclosed system operates in non-virtual mode, asindicated by processing decision 365.

Because the system is operating in non-virtual mode, the system sends aresponse message 382 to the client 370 including each of the data listitems 1-15. The client 370, utilizing the data representative of the 15sent data list items contained in response message 382, determines theappropriate way to display data list items 1-15 within the displaycontrol 310, as indicated by processing decision 372.

Referring again to the screen shot section 300, the display control 310,despite having received each of the data list items 1-15, only displaysData_List_Item_1 318 a, Data_List_Item_2 318 b, Data_List_Item_3 318 c,Data_List_Item_4 318 d, Data_List_Item_5 318 e, Data_List_Item_6 318 f,Data_List_Item_7 318 g, Data_List_Item_8 318 h, Data_List_Item_9 318 i,and Data_List_Item_10 318 j (i.e., data list items 1-10). Upondetermining how to appropriately display the received data list items1-15, the disclosed system enables an operator to scroll through thedisplayed items utilizing the slider 312 or the arrows 314 a and 314 b.Since the system is operating in non-virtual mode, any determinationsregarding which items to display in the display control 310 are made bythe client without sending additional requests for data to the server360.

Referring now to FIG. 4, display control 310 is illustrated in thescreen shot section 300 after an operator has used the slider 312 and/orthe arrows 314 a and 314 b to scroll downward through the displayed datalist items. In the display control 310 illustrated in FIG. 4,Data_List_Item_6 318 f, Data_List_Item_7 318 g, Data_List_Item_8 318 h,Data_List_Item_9 318 i, Data_List_Item_10 318 j, Data_List_Item_11 318k, Data_List_Item_12 318 l, Data_List_Item_13 318 m, Data_List_Item_14318 n, and Data_List_Item_15 318 o are displayed by the display control310. Moreover, the slider 312 is illustrated as positioned relativelydownwardly within the slider bar 313, indicating the relative positionof the displayed data list items within the entire set of data listitems 1-15.

Referring to the message flow diagram section 350 of FIG. 4, the client370 generates a scroll message 383 indicating that an operator has inputa desired scroll input. The scroll message includes data indicating theposition to which the operator has scrolled (not shown) and alsoincludes data indicating that the current size of the display control is10. Upon receiving the scroll message 383, the server determines thatthe total number of data list items to display remains 15, as indicatedby processing decision 361, and determines that the threshold remains0.4, as indicated by processing decision 362. Based on the receiveddisplay control size of 10, the system determines that the ratio remainsat a value of 0.67, as indicated by processing decision 363. It shouldbe appreciated that the ratio remains at a value of 0.67 due to the factthat neither the total quantity of items to be displayed nor the displaycontrol size (i.e., the two components of the ratio) has changed.Because the ratio still exceeds the threshold value, as indicated byprocessing decision 364, the system continues displaying the pluralityof data list items in non-virtual mode, as indicated by processingdecision 365.

It should be appreciated that because the system continues displayingthe data list items in non-virtual mode, the client 370 handles thedisplay of the correct subset of the display items in response to thescroll input by the operator. It should be further appreciated that invarious embodiments, the client 370 of the disclosed system is notconfigured to trap and handle a scroll event. For example, the client ofthe disclosed system may only send a message to the server 360 when itrequires additional data from the server. If the system is operating innon-virtual mode, it should be appreciated that the client 370 may notneed additional data from the server 360 for a simple scroll operation.

The screen shot section 300 of FIG. 5 illustrates the display control310 after an operator has used the resizer 316 to resize the displaycontrol 310. Specifically, in the illustrated embodiment, an operator atthe remote client 152 clicked and dragged the resize indicator 316 so asto shrink the display control in the vertical direction. Whereas inFIGS. 3 and 4 the display control 310 had a dimension of 9, the displaycontrol 310 of FIG. 5 is sized only to display Data_List_Item_9 318 i,Data_List_Item_10 318 j, Data_List_Item_11 318 k, Data_List_Item_12 318l, Data_List_Item_13 318 m, Data_List_Item_14 318 n, andData_List_Item_15 318 o.

Referring to the message flow diagram 380 of the message flow diagramsection 350 of FIG. 5, the client 370 sends a resize message 384 to theserver 360, indicating that an operator has modified the size of thedisplay control 310. The resize message 384 includes data indicatingthat the new control size (after resizing) is 7. The server 360 thusdetermines that the total number of items to display remains 15, asindicated by processing decision 361, and that the threshold valueremains 0.4, as indicated by processing decision 362. Based on thedisplay control size of 7 received in resize message 384, the server 360determines that the ratio between the display control size and the totalnumber of items to display is 0.47, as indicated by processing decision363. Once again, the system determines that the ratio exceeds thethreshold value, as indicated by processing decision 364, and determinesthat the system should continue operating in non-virtual mode, asindicated by processing decision 365. Therefore, the client 370 handlesappropriately displaying the data list items in the display control 310based on the data received from the server in response message 382 ofthe message flow diagram 380 of FIG. 3.

FIG. 6 illustrates the display control 310 in the screen section 300after the operator has again resized the display control 310.Specifically, the operator has again used the resizer 316 to reduce thevertical size of the display control 310. In the illustrated embodiment,the display control 310 of FIG. 6 displays only five data list itemsincluding Data_List_Item_11 318 k, Data_List_Item_12 318 l,Data_List_Item_13 318 m, Data_List_Item_14 318 n, and Data_List_Item_15318 o.

The message flow diagram section 350 of FIG. 6 illustrates a messageflow diagram 380 including two messages. Specifically, upon receiving aresize message 385 indicating a new display control size of 5, theserver 360 again determines that 15 data list items remain fordisplaying in the display control 310 and that the threshold valueremains at 0.4, as indicated by processing decisions 361 and 362,respectively. Based on the display control size received in the resizemessage 385, the server 360 calculates a ratio between the displaycontrol size and the total quantity of displayed items of 0.33, asindicated by processing decision 363. Because the ratio is less than thethreshold value of 0.4, as indicated by processing decision 364, thedisclosed system determines that data should be sent from the server 360to the client 370 in virtual mode, as indicated by processing decision365. Thus, the disclosed system sends a response message 386 includingdata representing data list items 11 to 15 to the client 370 for displayin the display control 310, as indicated by processing decision 372.

It should be appreciated that because the system is operating in virtualmode, the display control 310 does not need to determine which of theplurality of received data list items to display; rather, it displayseach of the list data items it received from the server 360 in themessage 386. It should be further appreciated that upon switching fromdisplaying the list items in non-virtual mode to displaying the listitems in virtual mode, the disclosed system may delete the stored listitems from the remote client 152. Alternatively, the disclosed systemmay continue to store previously sent list items and may treat anyadditional list items which are not stored as being sent based on avirtual mode of operation. In the embodiments illustrated in FIGS. 6 to9, the system deletes or otherwise removes any data stored on the client370 indicating data list items for display such that upon enteringvirtual mode, the disclosed system sends each data list item to bedisplayed based on the size and position of the display control 310.

FIG. 7 illustrates the display control 310 after receiving an input fromthe operator using either the slider 312 or the arrow buttons 314 a and314 b. Specifically, the operator indicated a scroll upward input suchthat Data_List_Item_9 318 i, Data_List_Item_10 318 j, Data_List_Item_11318 k, Data_List_Item_12 318 l, and Data_List_Item_13 318 m are visible,as opposed to data list items 318 k, 318 l, 318 m, 318 n, and 318 o asin FIG. 6. The message flow diagram section 350 of FIG. 7 illustrates amessage flow chart 380 corresponding to the scroll illustrated in thedisplay control section 300. Specifically, upon receiving a scrollmessage 387 from the client 370, the disclosed system determines thatthe total number of displayed items remains at 15, as indicated byprocessing decision 361, that the threshold value remains 0.4, asindicated by processing decision 362, that the ratio remains 0.33, asindicated by processing decision 363, and that because the ratio remainsless than the threshold value, the system continues to operate invirtual mode, as indicated by processing decisions 364 and 365. Theserver 360 responds to the scroll message by sending an appropriateresponse message 388 which includes data list items 9 and 10. It shouldbe appreciated that because the system is operating in virtual mode, theserver 360 determines that the client 370 did not receive items 9 and 10in its most recently received message, and thus sends the missing items.The client 370 then displays the appropriate list items 9-13, asindicated by processing decision 372.

FIG. 8 illustrates the display control 310 in the screen shot section300 after the operator has deleted all but 3 of the data list items 1-15from the display control 310. Specifically, all of the data list items,with the exception of Data_List_Item_3 318 c, Data_List_Item_4 318 d,and Data_List_Item_5 318 e have been removed from the display control310. It should be appreciated that the deleted data list items may beremoved in any appropriate way, such as by selecting and deleting usinga keyboard or mouse-type input device. In the illustrated embodiment,the operator did not resize the display control 310, resulting in emptyspace 319 within the display control. Because the displayed data listitems 318 c, 318 d, and 318 e are entirely displayable within thedisplay control 310, the display control 310 does not include a slider312 in the slider bar 313, and the arrows 314 a and 314 b are indicatedas being non-selectable.

The message flow diagram section 350 of FIG. 8 illustrates a messageflow diagram 380 beginning with the client 370 sending a delete datalist items message 389. The delete data list items message 389 includesdata indicating that list items 1, 2, and 6-15 are to be deleted. Themessage 389 further includes data indicating a control size of 5 fordisplay control 310. It should be appreciated that the control sizeexceeding the quantity of data list items results in the empty space 319of the display control. In response to the delete data items message,the server 360 does not delete the appropriate items from the storagedevice 118. Rather, the server just causes the items displayed in thedisplay control 310 to reflect the deletion. It should be appreciatedthat in alternative embodiments, the server may delete the items fromthe storage device 118 upon receiving such a delete data items message389.

Based on the received message, the server determines that the totalnumber of display items remaining (after deletion) is 3 items, asindicated by processing decision 361. The server 360 determines that thethreshold value remains 0.4, as indicated by processing decision 362.The server 360 calculates a new ratio of 1.33, indicated by processingdecision 363, which represents the ratio of the display control size (5)to the total number of items to be displayed (3). Because the ratioexceeds the threshold value, as indicated by processing decision 364,the server determines that the display mode should be non-virtual, asindicated by processing decision 365. The server therefore sends amessage 390 to the client 370 including data representing each of theremaining data list items—that is, data list items 3-5. The client 370displays the list items 318 c, 318 d, and 318 e in the display control,as indicated by processing decision 372. It should be appreciated thatthe client 370 displays the items in non-virtual mode—that is, theclient 370 handles determining which (if any) subset of the data listitems to display. It should thus be appreciated that FIG. 8 illustratesan impact on the ratio caused by deletion of data list items from thetotal set of data list items.

It should be further appreciated that sending a message from the client370 to the server 360 which adds data list items to the overall set ofdata list items may have a similar impact. Specifically, if the reverseoperation performed in FIG. 8 is performed (i.e., 12 data items areadded to the set of data list items), the disclosed system wouldcalculate a ratio of 5/15 or 0.33, which would be less than thethreshold value of 0.4. As a result, the system would determine itshould operate in non-virtual mode, and would send only the data itemswhich could be simultaneously displayed in the display control with asize of 5.

The disclosed system may be used in conjunction with software whichfacilitates thin client implementations of the remote client 152. Forexample, the disclosed system may be used in conjunction with softwarewhich sends only display data to a remote client 152. The remote client152 may not perform any processing; it may merely act as a remotemonitor or terminal for displaying output and receiving input generatedby the host device 100.

The disclosed host device 100 may also enable the remote client 152 toact as a thick client. That is, the disclosed host device 100 may enablethe remote client to send commands directly to the storage device 118and may rely on the remote client to perform most of the logic requiredto display the disclosed menu control. For example, the remote client152 may include software configured to determine whether the remoteclient 152 is operating in virtual or non-virtual mode, to determinewhich data items are required for display, and to generate appropriaterequest messages for sending to the host device 100.

Regardless of whether the host system 100 enables an operator at aremote client 152 acting as a thin client or a thick client to interactwith the host system 100 via a network 140, the disclosed system enablesan operator to remotely view a plurality of data list items using adisplay control which seamlessly determines whether to operate invirtual or non-virtual mode. Moreover, this determination may be made aplurality of times during the operator's browsing, navigation, andmodification of the list items while remaining invisible to theoperator. It should thus be appreciated that the disclosed systemenables efficient use of network resources wherein the efficiency isdetermined based on the capabilities of a remote display control.

In summary, a system and methods for providing access to a plurality oflist items including determining whether to display the list items invirtual mode by sending only the currently displayed items or innon-virtual mode by sending the full set of list items have beenprovided. It should be understood that various changes and modificationsto the presently preferred embodiments described herein will be apparentto those skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

1. A method of displaying a plurality of items at a remote location, themethod comprising: storing a threshold value; storing the plurality ofitems; determining a quantity associated with the plurality of items;receiving a request for data representing the plurality of items fromthe remote location; determining a relationship value indicative of arelationship between the a display control dimension and the quantityassociated with the plurality of items; conditioned on the relationshipvalue exceeding the threshold value, sending the data representing theplurality of items to the remote location for display; and conditionedon the relationship value not exceeding the threshold value, sending asubset of the data representing the plurality of items to the remotelocation for display.
 2. The method of claim 1, wherein the relationshipvalue is a first relationship value, and which includes receiving dataindicating a desired change in the quantity associated with theplurality of items and determining a second relationship valueindicative of the relationship between the display control dimension andthe changed quantity.
 3. The method of claim 2, wherein the dataindicating a desired change in the quantity associated with theplurality of items includes data indicating an addition or a deletion ofat least one item.
 4. The method of claim 1, wherein the threshold valueis based, at least in part, on a set of hardware specifications of amachine at the remote location.
 5. The method of claim 4, wherein theset of hardware specifications includes at least one selected from thegroup consisting of: a processor speed of the machine, a monitor size ofthe machine, and an amount of memory of the machine.
 6. The method ofclaim 1, wherein the threshold value is based, at least in part, on anetwork connection speed of a network.
 7. The method of claim 1, whereindetermining the relationship value includes calculating a ratio betweenthe display control dimension and the quantity associated with theplurality of items.
 8. The method of claim 1, wherein the displaycontrol dimension reflects a quantity of items simultaneouslydisplayable by the display control.
 9. The method of claim 1, whereinthe display control dimension reflects a quantity of pixels of a heightof the display control.
 10. The method of claim 1, wherein the quantityassociated with the plurality of items indicates a number of theplurality of items.
 11. The method of claim 1, wherein the quantityassociated with the plurality of items indicates a storage size of theplurality of items in bytes.
 12. The method of claim 1, wherein thesubset of the data is a first subset, and which includes, conditioned onthe relationship value not exceeding the threshold, sending a second,different subset of the data upon receiving data indicating a scrollinput.
 13. The method of claim 1, wherein at least one of the items isassociated with content data, and which includes, conditioned on therelationship value exceeding the threshold value, sending the datarepresentative of the plurality of items and the associated content datato the remote location.
 14. The method of claim 1, wherein at least oneof the items is associated with content data, and which includes,conditioned on the relationship value not exceeding the threshold value,sending the subset of the data representing the plurality of items andthe content data associated with the items represented by the subset ofthe data to the remote location.
 15. The method of claim 1, whichincludes receiving the display control dimension from the remotelocation.
 16. The method of claim 1, wherein the request for datarepresenting the plurality of items includes information about a displaycontrol, the information about the display control including informationrepresentative of the display control dimension.
 17. A method of sendingdata for display at a destination, the method comprising: receiving fromthe destination a request for the data; determining a quantityindicative of the size of the data; determining a comparison ratiobetween the quantity indicative of the size of the data and a displaycontrol size; conditioned on the comparison ratio being in a firstquantifiable relationship with a threshold ratio, sending a subset ofthe data to the destination for display; and conditioned on thecomparison ratio being in a second quantifiable relationship with thethreshold ratio, sending the data to the destination for display.
 18. Asystem for sending data for display at a destination, the systemcomprising: at least one processor; and at least one memory device whichstores a plurality of instructions which, when executed by the at leastone processor, cause the at least one processor to operate with the atleast one memory device to: receive from the destination a request forthe data; determine a quantity indicative of the size of the data;determine a comparison ratio between the quantity indicative of the sizeof the data and a display control size; conditioned on the comparisonratio being in a first quantifiable relationship with a threshold ratio,send a subset of the data to the destination for display; andconditioned on the comparison ratio being in a second quantifiablerelationship with the threshold ratio, send the data to the destinationfor display.